Pen



FIG. 1 is a front right side view of a pen showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines in the drawings are included for the purpose of showing portions of the pen that form no part of the claimed design. The surfaces between the solid lines are entirely unclaimed. 

CLAIM The ornamental design for a pen, as shown and described. 